The present invention relates to the utilization of plastic optical fiber, and, more particularly, to the finishing of an end of a plastic optical fiber for insertion into an optical connector.
Optical plastic fibers are in general easy to work with and are economical. An ongoing problem with the utilization of plastic optical fibers has been the problem of finishing the ends of a plastic optical fiber before or after insertion into an optical connector. The prior art finishing techniques have yielded connectors with a high insertion loss. These losses are typically in the 1.5 dB to 2.0 dB range. These insertion losses are high. For example, multimode connectors made with silica fibers are typically less than 0.5 dB. Within the prior art, the finishing of ends of plastic optical fibers in the field and the manufacturing environment have utilized two or three different grits of optical polishing paper to polish the end of the optical fiber. The utilization of optical polishing paper has resulted in the high insertion losses previously mentioned. Also within the prior art, another method is used to finish the ends of plastic optical fibers. This other method is referred to as hot plate end finishing. The hot plate end finishing method typically results in losses in the 1.5-2.0 dB range.
A departure in the art is achieved by an apparatus and a method for finishing an end of a plastic optical fiber by ablating the end of the plastic optical fiber by utilizing an Excimer laser. A high powered ultraviolet beam of light from the laser is absorbed by the end of the fiber and ablates the first few tens of microns of the fiber. This process removes material containing residual cracks and fissures to flatten the end of the fiber. The optical fiber is then ready to make a low loss interface with a source, a detector, or another optical fiber.
Other and further aspects of the present invention will become apparent during the course of the following description and by reference to the accompanying drawing.